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authorwolfbeast <mcwerewolf@gmail.com>2018-05-12 11:09:44 +0200
committerwolfbeast <mcwerewolf@gmail.com>2018-05-12 11:09:44 +0200
commitcfe5ef4ac7cd59f094b538252161ad74223c47da (patch)
treee5c0ee7e70db84bd2bfc6062784006769e9df730 /widget/gonk/GonkMemoryPressureMonitoring.cpp
parent28cf922aa9af4d4b8e0a3ce91dc1270a55986909 (diff)
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Remove Gonk build directories
Diffstat (limited to 'widget/gonk/GonkMemoryPressureMonitoring.cpp')
-rw-r--r--widget/gonk/GonkMemoryPressureMonitoring.cpp359
1 files changed, 0 insertions, 359 deletions
diff --git a/widget/gonk/GonkMemoryPressureMonitoring.cpp b/widget/gonk/GonkMemoryPressureMonitoring.cpp
deleted file mode 100644
index 0fafb37cf..000000000
--- a/widget/gonk/GonkMemoryPressureMonitoring.cpp
+++ /dev/null
@@ -1,359 +0,0 @@
-/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
-/* vim: set ts=2 et sw=2 tw=80: */
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-#include <android/log.h>
-#include <errno.h>
-#include <fcntl.h>
-#include <poll.h>
-#include <sys/sysinfo.h>
-
-#include "GonkMemoryPressureMonitoring.h"
-#include "mozilla/ArrayUtils.h"
-#include "mozilla/FileUtils.h"
-#include "mozilla/Monitor.h"
-#include "mozilla/Preferences.h"
-#include "mozilla/ProcessPriorityManager.h"
-#include "mozilla/Services.h"
-#include "nsIObserver.h"
-#include "nsIObserverService.h"
-#include "nsMemoryPressure.h"
-#include "nsPrintfCString.h"
-#include "nsThreadUtils.h"
-
-#define LOG(args...) \
- __android_log_print(ANDROID_LOG_INFO, "GonkMemoryPressure" , ## args)
-
-using namespace mozilla;
-
-namespace {
-
-/**
- * MemoryPressureWatcher watches sysfs from its own thread to notice when the
- * system is under memory pressure. When we observe memory pressure, we use
- * MemoryPressureRunnable to notify observers that they should release memory.
- *
- * When the system is under memory pressure, we don't want to constantly fire
- * memory-pressure events. So instead, we try to detect when sysfs indicates
- * that we're no longer under memory pressure, and only then start firing events
- * again.
- *
- * (This is a bit problematic because we can't poll() to detect when we're no
- * longer under memory pressure; instead we have to periodically read the sysfs
- * node. If we remain under memory pressure for a long time, this means we'll
- * continue waking up to read from the node for a long time, potentially wasting
- * battery life. Hopefully we don't hit this case in practice! We write to
- * logcat each time we go around this loop so it's at least noticable.)
- *
- * Shutting down safely is a bit of a chore. XPCOM won't shut down until all
- * threads exit, so we need to exit the Run() method below on shutdown. But our
- * thread might be blocked in one of two situations: We might be poll()'ing the
- * sysfs node waiting for memory pressure to occur, or we might be asleep
- * waiting to read() the sysfs node to see if we're no longer under memory
- * pressure.
- *
- * To let us wake up from the poll(), we poll() not just the sysfs node but also
- * a pipe, which we write to on shutdown. To let us wake up from sleeping
- * between read()s, we sleep by Wait()'ing on a monitor, which we notify on
- * shutdown.
- */
-class MemoryPressureWatcher final
- : public nsIRunnable
- , public nsIObserver
-{
-public:
- MemoryPressureWatcher()
- : mMonitor("MemoryPressureWatcher")
- , mLowMemTriggerKB(0)
- , mPageSize(0)
- , mShuttingDown(false)
- , mTriggerFd(-1)
- , mShutdownPipeRead(-1)
- , mShutdownPipeWrite(-1)
- {
- }
-
- NS_DECL_THREADSAFE_ISUPPORTS
-
- nsresult Init()
- {
- nsCOMPtr<nsIObserverService> os = services::GetObserverService();
- NS_ENSURE_STATE(os);
-
- // The observer service holds us alive.
- os->AddObserver(this, NS_XPCOM_SHUTDOWN_OBSERVER_ID, /* ownsWeak */ false);
-
- // Initialize the internal state
- mPageSize = sysconf(_SC_PAGESIZE);
- ReadPrefs();
- nsresult rv = OpenFiles();
- NS_ENSURE_SUCCESS(rv, rv);
- SetLowMemTrigger(mSoftLowMemTriggerKB);
-
- return NS_OK;
- }
-
- NS_IMETHOD Observe(nsISupports* aSubject, const char* aTopic,
- const char16_t* aData)
- {
- MOZ_ASSERT(strcmp(aTopic, NS_XPCOM_SHUTDOWN_OBSERVER_ID) == 0);
- LOG("Observed XPCOM shutdown.");
-
- MonitorAutoLock lock(mMonitor);
- mShuttingDown = true;
- mMonitor.Notify();
-
- int rv;
- do {
- // Write something to the pipe; doesn't matter what.
- uint32_t dummy = 0;
- rv = write(mShutdownPipeWrite, &dummy, sizeof(dummy));
- } while(rv == -1 && errno == EINTR);
-
- return NS_OK;
- }
-
- NS_IMETHOD Run() override
- {
- MOZ_ASSERT(!NS_IsMainThread());
-
- int triggerResetTimeout = -1;
- bool memoryPressure;
- nsresult rv = CheckForMemoryPressure(&memoryPressure);
- NS_ENSURE_SUCCESS(rv, rv);
-
- while (true) {
- // Wait for a notification on mTriggerFd or for data to be written to
- // mShutdownPipeWrite. (poll(mTriggerFd, POLLPRI) blocks until we're
- // under memory pressure or until we time out, the time out is used
- // to adjust the trigger level after a memory pressure event.)
- struct pollfd pollfds[2];
- pollfds[0].fd = mTriggerFd;
- pollfds[0].events = POLLPRI;
- pollfds[1].fd = mShutdownPipeRead;
- pollfds[1].events = POLLIN;
-
- int pollRv = MOZ_TEMP_FAILURE_RETRY(
- poll(pollfds, ArrayLength(pollfds), triggerResetTimeout)
- );
-
- if (pollRv == 0) {
- // Timed out, adjust the trigger and update the timeout.
- triggerResetTimeout = AdjustTrigger(triggerResetTimeout);
- continue;
- }
-
- if (pollfds[1].revents) {
- // Something was written to our shutdown pipe; we're outta here.
- LOG("shutting down (1)");
- return NS_OK;
- }
-
- // If pollfds[1] isn't happening, pollfds[0] ought to be!
- if (!(pollfds[0].revents & POLLPRI)) {
- LOG("Unexpected revents value after poll(): %d. "
- "Shutting down GonkMemoryPressureMonitoring.", pollfds[0].revents);
- return NS_ERROR_FAILURE;
- }
-
- // POLLPRI on mTriggerFd indicates that we're in a low-memory situation.
- // We could read lowMemFd to double-check, but we've observed that the
- // read sometimes completes after the memory-pressure event is over, so
- // let's just believe the result of poll().
- rv = DispatchMemoryPressure(MemPressure_New);
- NS_ENSURE_SUCCESS(rv, rv);
-
- // Move to the hard level if we're on the soft one.
- if (mLowMemTriggerKB > mHardLowMemTriggerKB) {
- SetLowMemTrigger(mHardLowMemTriggerKB);
- }
-
- // Manually check mTriggerFd until we observe that memory pressure is
- // over. We won't fire any more low-memory events until we observe that
- // we're no longer under pressure. Instead, we fire low-memory-ongoing
- // events, which cause processes to keep flushing caches but will not
- // trigger expensive GCs and other attempts to save memory that are
- // likely futile at this point.
- do {
- {
- MonitorAutoLock lock(mMonitor);
-
- // We need to check mShuttingDown before we wait here, in order to
- // catch a shutdown signal sent after we poll()'ed mShutdownPipeRead
- // above but before we started waiting on the monitor. But we don't
- // need to check after we wait, because we'll either do another
- // iteration of this inner loop, in which case we'll check
- // mShuttingDown, or we'll exit this loop and do another iteration
- // of the outer loop, in which case we'll check the shutdown pipe.
- if (mShuttingDown) {
- LOG("shutting down (2)");
- return NS_OK;
- }
- mMonitor.Wait(PR_MillisecondsToInterval(mPollMS));
- }
-
- LOG("Checking to see if memory pressure is over.");
- rv = CheckForMemoryPressure(&memoryPressure);
- NS_ENSURE_SUCCESS(rv, rv);
-
- if (memoryPressure) {
- rv = DispatchMemoryPressure(MemPressure_Ongoing);
- NS_ENSURE_SUCCESS(rv, rv);
- continue;
- }
- } while (false);
-
- if (XRE_IsParentProcess()) {
- // The main process will try to adjust the trigger.
- triggerResetTimeout = mPollMS * 2;
- }
-
- LOG("Memory pressure is over.");
- }
-
- return NS_OK;
- }
-
-protected:
- ~MemoryPressureWatcher() {}
-
-private:
- void ReadPrefs() {
- // While we're under memory pressure, we periodically read()
- // notify_trigger_active to try and see when we're no longer under memory
- // pressure. mPollMS indicates how many milliseconds we wait between those
- // read()s.
- Preferences::AddUintVarCache(&mPollMS,
- "gonk.systemMemoryPressureRecoveryPollMS", /* default */ 5000);
-
- // We have two values for the notify trigger, a soft one which is triggered
- // before we start killing background applications and an hard one which is
- // after we've killed background applications but before we start killing
- // foreground ones.
- Preferences::AddUintVarCache(&mSoftLowMemTriggerKB,
- "gonk.notifySoftLowMemUnderKB", /* default */ 43008);
- Preferences::AddUintVarCache(&mHardLowMemTriggerKB,
- "gonk.notifyHardLowMemUnderKB", /* default */ 14336);
- }
-
- nsresult OpenFiles() {
- mTriggerFd = open("/sys/kernel/mm/lowmemkiller/notify_trigger_active",
- O_RDONLY | O_CLOEXEC);
- NS_ENSURE_STATE(mTriggerFd != -1);
-
- int pipes[2];
- NS_ENSURE_STATE(!pipe(pipes));
- mShutdownPipeRead = pipes[0];
- mShutdownPipeWrite = pipes[1];
- return NS_OK;
- }
-
- /**
- * Set the low memory trigger to the specified value, this can be done by
- * the main process alone.
- */
- void SetLowMemTrigger(uint32_t aValue) {
- if (XRE_IsParentProcess()) {
- nsPrintfCString str("%ld", (aValue * 1024) / mPageSize);
- if (WriteSysFile("/sys/module/lowmemorykiller/parameters/notify_trigger",
- str.get())) {
- mLowMemTriggerKB = aValue;
- }
- }
- }
-
- /**
- * Read from the trigger file descriptor and determine whether we're
- * currently under memory pressure.
- *
- * We don't expect this method to block.
- */
- nsresult CheckForMemoryPressure(bool* aOut)
- {
- *aOut = false;
-
- lseek(mTriggerFd, 0, SEEK_SET);
-
- char buf[2];
- int nread = MOZ_TEMP_FAILURE_RETRY(read(mTriggerFd, buf, sizeof(buf)));
- NS_ENSURE_STATE(nread == 2);
-
- // The notify_trigger_active sysfs node should contain either "0\n" or
- // "1\n". The latter indicates memory pressure.
- *aOut = (buf[0] == '1');
- return NS_OK;
- }
-
- int AdjustTrigger(int timeout)
- {
- if (!XRE_IsParentProcess()) {
- return -1; // Only the main process can adjust the trigger.
- }
-
- struct sysinfo info;
- int rv = sysinfo(&info);
- if (rv < 0) {
- return -1; // Without system information we're blind, bail out.
- }
-
- size_t freeMemory = (info.freeram * info.mem_unit) / 1024;
-
- if (freeMemory > mSoftLowMemTriggerKB) {
- SetLowMemTrigger(mSoftLowMemTriggerKB);
- return -1; // Trigger adjusted, wait indefinitely.
- }
-
- // Wait again but double the duration, max once per day.
- return std::min(86400000, timeout * 2);
- }
-
- /**
- * Dispatch the specified memory pressure event unless a high-priority
- * process is present. If a high-priority process is present then it's likely
- * responding to an urgent event (an incoming call or message for example) so
- * avoid wasting CPU time responding to low-memory events.
- */
- nsresult DispatchMemoryPressure(MemoryPressureState state)
- {
- if (ProcessPriorityManager::AnyProcessHasHighPriority()) {
- return NS_OK;
- }
-
- return NS_DispatchMemoryPressure(state);
- }
-
- Monitor mMonitor;
- uint32_t mPollMS; // Ongoing pressure poll delay
- uint32_t mSoftLowMemTriggerKB; // Soft memory pressure level
- uint32_t mHardLowMemTriggerKB; // Hard memory pressure level
- uint32_t mLowMemTriggerKB; // Current value of the trigger
- size_t mPageSize;
- bool mShuttingDown;
-
- ScopedClose mTriggerFd;
- ScopedClose mShutdownPipeRead;
- ScopedClose mShutdownPipeWrite;
-};
-
-NS_IMPL_ISUPPORTS(MemoryPressureWatcher, nsIRunnable, nsIObserver);
-
-} // namespace
-
-namespace mozilla {
-
-void
-InitGonkMemoryPressureMonitoring()
-{
- // memoryPressureWatcher is held alive by the observer service.
- RefPtr<MemoryPressureWatcher> memoryPressureWatcher =
- new MemoryPressureWatcher();
- NS_ENSURE_SUCCESS_VOID(memoryPressureWatcher->Init());
-
- nsCOMPtr<nsIThread> thread;
- NS_NewNamedThread("MemoryPressure", getter_AddRefs(thread),
- memoryPressureWatcher);
-}
-
-} // namespace mozilla